/**
 * Software License, Version 1.0
 * 
 * Copyright 2003 The Trustees of Indiana University.  All rights reserved.
 * 
 *
 *Redistribution and use in source and binary forms, with or without 
 *modification, are permitted provided that the following conditions are met:
 *
 *1) All redistributions of source code must retain the above copyright notice,
 * the list of authors in the original source code, this list of conditions and
 * the disclaimer listed in this license;
 *2) All redistributions in binary form must reproduce the above copyright 
 * notice, this list of conditions and the disclaimer listed in this license in
 * the documentation and/or other materials provided with the distribution;
 *3) Any documentation included with all redistributions must include the 
 * following acknowledgement:
 *
 *"This product includes software developed by the Community Grids Lab. For 
 * further information contact the Community Grids Lab at 
 * http://communitygrids.iu.edu/."
 *
 * Alternatively, this acknowledgement may appear in the software itself, and 
 * wherever such third-party acknowledgments normally appear.
 * 
 *4) The name Indiana University or Community Grids Lab or NaradaBrokering, 
 * shall not be used to endorse or promote products derived from this software 
 * without prior written permission from Indiana University.  For written 
 * permission, please contact the Advanced Research and Technology Institute 
 * ("ARTI") at 351 West 10th Street, Indianapolis, Indiana 46202.
 *5) Products derived from this software may not be called NaradaBrokering, 
 * nor may Indiana University or Community Grids Lab or NaradaBrokering appear
 * in their name, without prior written permission of ARTI.
 * 
 *
 * Indiana University provides no reassurances that the source code provided 
 * does not infringe the patent or any other intellectual property rights of 
 * any other entity.  Indiana University disclaims any liability to any 
 * recipient for claims brought by any other entity based on infringement of 
 * intellectual property rights or otherwise.  
 *
 *LICENSEE UNDERSTANDS THAT SOFTWARE IS PROVIDED "AS IS" FOR WHICH NO 
 *WARRANTIES AS TO CAPABILITIES OR ACCURACY ARE MADE. INDIANA UNIVERSITY GIVES
 *NO WARRANTIES AND MAKES NO REPRESENTATION THAT SOFTWARE IS FREE OF 
 *INFRINGEMENT OF THIRD PARTY PATENT, COPYRIGHT, OR OTHER PROPRIETARY RIGHTS. 
 *INDIANA UNIVERSITY MAKES NO WARRANTIES THAT SOFTWARE IS FREE FROM "BUGS", 
 *"VIRUSES", "TROJAN HORSES", "TRAP DOORS", "WORMS", OR OTHER HARMFUL CODE.  
 *LICENSEE ASSUMES THE ENTIRE RISK AS TO THE PERFORMANCE OF SOFTWARE AND/OR 
 *ASSOCIATED MATERIALS, AND TO THE PERFORMANCE AND VALIDITY OF INFORMATION 
 *GENERATED USING SOFTWARE.
 */
package cgl.narada.matching.tagvalue;

import java.util.Hashtable;
import java.util.StringTokenizer;
import java.util.Vector;

import cgl.narada.util.ByteUtilities;
/** The event class which we use to perform matching on the profile graph
    constructed using the general matching algorithm.
    
    @author Shrideep Pallickara
    $Revision$
    $Date$
*/

public class MEvent implements MatchingDebugFlags{
  private Hashtable tagValues;
  private Vector tags; 
  private int  depth=0;
  private String eventString;

  /** The timestamp and compensationLength are introduced for the sole
      purpose of gathering performance numbers */
  private long timeStamp;
  private int compensationLength;
  
  private int messageSize;

  /** The MEvent constructor.
      @param eventString The event string that we use to construct the
      String. 
      @param messageSize This fixes the size of the message, by padding extra
      bytes.
  */
  public MEvent(String eventString, int messageSize) {
    this.eventString = eventString;
    tagValues = new Hashtable();
    tags = new Vector();
    populateTagsAndValues(eventString);
    compensationLength = messageSize - ( 2 + eventString.length() 
					 + 8 /** timestamp */ + 
					 2 /** compensationLength */);
    if (compensationLength < 0) {
      compensationLength =0;
    }    
    timeStamp = System.currentTimeMillis();
  }
  
  
  /** This MEvent constructor is used only by the JmsEventRoutingProtocol
      @param eventString The event string that we use to construct the
      String.
  */
  public MEvent(String eventString) {
    this.eventString = eventString;
    tagValues = new Hashtable();
    tags = new Vector();
    populateTagsAndValues(eventString);
    //timeStamp = System.currentTimeMillis();
  }     
      

  /** This method serves to unmarshall an event stream received over the
      link. The corresponding marshalling method for the event is contained
      within the getBytes() method.
      @param eventBytes The marshalled stream of event bytes that are
      received over a link.
  */
  public MEvent(byte[] eventBytes) {
    messageSize = eventBytes.length;
    int offset =0;
    /** Unmarshall the eventLength */
    byte[] lengthBytes = new byte[2];
    System.arraycopy(eventBytes, offset, lengthBytes,0, 2);
    offset+=2;
    int eventLength = (int) ByteUtilities.getShort(lengthBytes);
    /** Unmarshall the event */
    byte[] eventStringBytes = new byte[eventLength];
    System.arraycopy(eventBytes, offset, eventStringBytes, 0, eventLength);
    eventString =  new String(eventStringBytes, 0, eventLength);
    offset+=eventLength;
    if (MEvent_Debug)
      System.out.println("Event ->" +eventString);
    
    /** Unmarshall the time stamp */
    byte[] stampBytes = new byte[8];
    System.arraycopy(eventBytes, offset, stampBytes,0, 8);
    timeStamp = ByteUtilities.getLong(stampBytes);
    offset+=8;

    /** Unmarshall the compensation Length */
    System.arraycopy(eventBytes, offset, lengthBytes,0, 2);
    offset+=2;
    compensationLength = (int)ByteUtilities.getShort(lengthBytes);
    
    tagValues = new Hashtable();
    tags = new Vector();
    populateTagsAndValues(eventString);
    
  }
  
  /** This method returns the timestamp associated with the event 
      @return The timeStamp
   */
  public long getTimeStamp() {
    return timeStamp;
  }
  
  public void setTimeStamp(long timeStamp) {
    this.timeStamp = timeStamp;
  }

  public int getMessageSize() {
    return messageSize;
  }
  
  public void resetLocalPointer() {
    depth=0;
  }
  
  private void populateTagsAndValues(String eventString) {
    StringTokenizer tok = new StringTokenizer(eventString, ",");
    int i=0;
    String tag;
    String value;
    if (MEvent_Debug)
      System.out.print("TagValue Pair ");
    while (tok.hasMoreTokens()) {
      i++;
      String tagValuePair = tok.nextToken();
      if (MEvent_Debug)
	System.out.println("  ("+ i + ")->" + tagValuePair);
      StringTokenizer tok2 = new StringTokenizer(tagValuePair, "=");
      if(tok2.countTokens() == 2) {
	tag = tok2.nextToken();
	value = tok2.nextToken();
	tags.addElement(tag);
	tagValues.put(tag, value);
      } else {
	System.out.println("Malformed TAG=VALUE Pair  in event string " 
			   + eventString);
      }
    }
  }

  /** This method returns the value associated with a tag 
      @param tag The tag for which we are seeking a value.
   */

  public String getTagValue(String tag) {
    return (String)tagValues.get(tag);
  }
  
  /** This returns the next tag, that is contained in the <i><tag, value></i>
      pairs associated with the event.
      @return The next tag in the tag-value sequence */
  public String getNextTag() {
    if (depth > tags.size()-1) {
      return null;
    }
    String tag = (String)tags.elementAt(depth);
    depth++;
    return tag;
  }

  /** This method returns the MEvent as a stream of bytes, the unmarshalling
      counterpart to this marshalling scheme is contained within one of 
      the MEvent constructors 
      @return The byte stream representation of the MEvent
  */
  public byte[] getBytes() {
    
    int bufferLength;
    int eventLength = eventString.length();
    bufferLength = 2 /** specify the event length */ 
      + eventLength  /** The length of the event string */
      + 8 /** This is for testing purposes and includes the timeStamp */
      + 2 /** specifies the size compensation length */ +
      + compensationLength;
    
    int offset=0;
    byte[] eventBytes = new byte[bufferLength];
    
    /** Marshalling the event length in two bytes */
    System.arraycopy(ByteUtilities.getBytes((short)eventLength), 0,
		     eventBytes, offset, 2);
    offset+=2;
    /** Marshall the event string */
    System.arraycopy(eventString.getBytes(), 0, 
		     eventBytes, offset, eventLength);
    offset += eventLength;
    
    /** Marshall the timeStamp */
    System.arraycopy(ByteUtilities.getBytes(timeStamp), 0,
		     eventBytes, offset, 8);
    offset+=8;
    
    /** Marshall the size compensationLength */
    System.arraycopy(ByteUtilities.getBytes((short)compensationLength), 0,
		     eventBytes, offset, 2);
    offset +=2;
    
    return eventBytes;    
  }  

  /** Provides a string representation of the event.
      @return String representation of the event*/
  public String toString() {
    return eventString;
  }
  
  public static void main(String[] args) {
    MEvent mEvent = new MEvent("A=a, B=b, C=c", 50);
    System.out.println(mEvent + " timeStamp-> " + mEvent.getTimeStamp());
    MEvent mEvent2 = new MEvent(mEvent.getBytes());
    System.out.println(mEvent2 + " timeStamp-> " + mEvent2.getTimeStamp() 
		       + " messageSize ->"+ mEvent2.getMessageSize());
  }
  
}







